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Comment by kjkjadksj | Hacker News Reader

The only things an older frame won’t accommodate is electronic shifting and disk brakes. You can run 12 speed its the same cassette width as its always been since probably 7 speed. Stuff like external cables actually are better for you as someone who isn’t a pro cyclist since shifting is smoother without under handle wraps, cables last longer with less tension in the brifter. Easier to service yourself than running the cables in the stem or frame. 8 speed better too because the chain and cassettes will last forever vs thinner higher speed stuff. Gear range is probably the same just with more increments so you get away with fewer shifts on 8 speed and just use your legs to find the gear and cadence balance. People did big descents just fine on rim brakes for decades until they came out with disk and made it seem like an issue.

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i don't know if braking performance is the main reason for disk brakes.

I suspect the biggest benefit is bike makers get to sell new bikes to people who don't need new bikes.

For professional riders who don't buy their own bikes, it's probably more about areo, and maybe weight, as the rims don't need a braking surface. They have more creativity with the shape and material. They only brake for emergencies and going into a corner on a downhill. A tiny fraction of a stage. The areo benefit is for the full length of the stage.

I don't know much about physics but even if the weight of the disks is more than rims brakes, the weight being closer to the centre of the wheel might be a benefit. I suspect in terms of performance, aero is the biggest benefit, though.

even the 12 speed cassettes, from what I've read, accelerating smoothly isn't the main point. for a professional rider, they spend a lot more time at the same speed than they do accelerating. so being able to dial in the perfect gear for the speed, wind and gradient is more important than being able to accelerate smoothly.

You gain different rim designs sure. But you also lose out on fork innovation as the disk side of the fork is now particularly strengthened. I wouldn’t be surprised if there are some pro rider who would still ride rims if their sponsors allowed for it.

Aero matters a lot, even for enthusiastic amateurs. You're spot on about wheel shape being more flexible with disc brakes vs. rim. Materials matter here, too -- early carbon wheels were crap at stopping vs alloy because the rim brake tracks were iffy on the carbon, and if you let them get too hot on a descent you'd ruin the wheel. But carbon wheels are an ENORMOUS upgrade over alloy in terms of weight, and in terms of aerodynamics, so the desire for carbon helped fuel the shift to disc braking.

Discs are also absolutely better at stopping the bike, especially if it's hilly and SUPER especially if it's wet (or muddy, which is why off road bikes took to disc first).

Even in a flat place like Houston where we never would've gone to disc in the absence of market forces, we all realized quickly how much nicer they were. It's a definite upgrade.

You're also right about the cassette. More cogs mean we can have a wider range AND preserve the small steps between them, which is great for finding the right cadence in a paceline just as it is for accelerating.

Aero doesn’t really matter until you are riding at like 25+ mph. Internal cables are like a couple watt reduction at high speeds. Sure it matters for pros when a race is determined by seconds or less and that makes or breaks your career. For commuters and people riding for fitness though? Absolutely not. If you are riding for fitness wouldn’t you actually want a bike with more drag like all those people running with weighted vests and parachutes?

>Stuff like external cables actually are better for you as someone who isn’t a pro cyclist since shifting is smoother without under handle wraps, cables last longer with less tension in the brifter.

My bike doesn't have cables at all, since SRAM's electronic groups are wireless, and the brakes are hydraulic.

Actual gear range on a modern 11- or 12-speed bike can be FAR wider than you'd get with 7- or 8-. On gravel bikes where close ratios aren't important you can dwarf an 80s bike's range with a 1x setup. On road bikes, you can keep tight ratios that are great for faster paceline rides while still having a wider gear range.

I mean, then as now faster riders love a straight block cassette, right? In 1989 that might've meant 13-25 or so, with 7 or 8 cogs. My Giant is 10-28 with TWELVE cogs, but 10-30 and 10-33 are available, all of which preserve 1-tooth transitions at the low end of the block.

>People did big descents just fine on rim brakes for decades until they came out with disk and made it seem like an issue.

People had big families just fine for hundreds of years until they came out with vaccines and made it seem like an issue.

I mean, I kid, but in hilly or wet places disc brakes are a giant boon.

Well someone who isn’t a pro cyclist doesn’t care about pacetime rides. I commute. 11-28 is fine on 8 speed. If I am out of gear I shift or pedal faster or slower. Not a huge ask. My chains are also like $10 and don’t stretch for years.

Electronic shifting I see as a con. Di2 at least is not serviceable and reaches an end of life. I am not as familiar with sram but I assume its the same. Either way just yet another old thing (index shifting) served to you in a new way that needs yet another battery to charge and eventually replace. Shifting is plenty fast on a mechanical brifter.

I have no interest in hydraulics and bleeding brakes. Brake cables stay in spec basically forever if they are stainless steel for the most part. By the time you’ve fouled up a mechanical system you are talking years of neglect exposure to the elements type wear that would do a number to any other bike system all the same.

Wet no issue the rim calipers squeegie off the water in the first rotation. The real limit of the reaction here isn’t the braking system. It is the tires. Even cheap ancient rim brakes are sufficiently overpowered to lock up a bike wheel even on new tires in dry conditions. Let alone wet.

Imo a lot of this tech is marketing vs true innovations. I mean brifter designs that shear off the end of the shift cable just because of rider ocd wanting it under the wraps, come on. Just that one marketing driven change has lead to diminished shifting experience and more difficult servicing for the end user. And basically all newish paradigms over the last 10-15 years of road bikes fall into this where its a dual edged sword that really only benefits the people racing professionally who have a justification to demand each and every legal free watt from a system, while hurting you the consumer with more expensive bikes, components, more expensive and complicated service, more forced obsolescence and eliminating old oem patterns of spare parts. We really did peak at 10spd side exit mechanical imo. Although 8 speed is more reliable and stronger components with wider tolerance to derailleur adjustment.

>Well someone who isn’t a pro cyclist doesn’t care about pacetime rides.

You have a very narrow view of cycling, I think. Plenty of amateurs do fast paceline riding. It's a huge part of the hobby.

Sure. And they did that just fine on 8spd too when that was the dura ace option. Either way people aren’t really buying straight blocks. They are buying like 11-36. And probably don’t use the 11.

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